This invention relates generally to manual exercisers suitable for athletic or therapeutic purposes, and more particularly to an articulated exercise bar formed by left and right hand weighted arms joined together by a rotatable hinge assembly which renders the bar capable of undergoing complex motions which bring into play and develop many of the muscles in the muscular system associated with the user's arms which are uninvolved in conventional arm exercisers.
In contemporary society, large-scale mechanization has sharply reduced the need for an expenditure of physical energy in the production of goods and services. Indeed, the aim of most inventions is to provide a labor-saving device to supplant human effort. But while modern man has been relieved of the Biblical injunction to earn his daily bread by the sweat of his brow, this has been a mixed blessing; for the resultant inactivity has given rise in affluent societies to serious obesity problems and has impaired the ability of many persons to carry out their normal tasks with a reasonable degree of efficiency.
To remediate many of the physical fitness problems of the sedentary individual, various forms of exercisers have been conrived that are designed to develop muscular strength and endurance. By muscular strength is meant the measurable strength of muscles as determined by a single maximum contraction, and by muscular endurance is meant the ability of muscles to perform work for a given time period.
Muscles consist of many fibers held together by connective tissue and having the power to contract and relax and thereby perform the movement and the vital processes of the organism. The voluntary of striated muscles which are subject to the human will and control the body are attached by tendons to the skeleton. They constitute much of the body weight and appear as lean flesh.
Most manual exercisers in current use fall either into the isometric or isotonic class. An isometric exerciser is designed to sustain one muscular contraction and therefore operates on static tension, whereas an isotonic exerciser adapted to repeatedly raise or lower a weight or other load brings into play dynamic tension.
In a review by the President's Council on Physical Fitness and Sports of the research carried out on the comparative effects of isometric and isotonic training programs, the Council indicated a preference for the isotonic over the isometric form and concluded that isotonic training is superior in developing muscular strength and in improving muscular endurance. The Council pointed out that motivation is greater in isotonic exercising, for the participant can see what is being accomplished and explicit goals may be set.
Muscular power represents the ability to release maximum muscular force in the shortest time. Muscular strength is the strength of muscles as determined by a single maximum contraction, while muscular endurance is the ability of muscles to perform work for a given period of time. One may develop muscular power, strength and endurance by the use of bar bells, but the manipulation of bar bells up and down and sideways does not engage all of the shoulder and neck muscles as well as the arm and wrist muscles, and may therefore result in uneven development.
Other types of exercisers which make use of telescoping exercise bars that are joined together by a spring and pulled apart by the hands of the user, also result in uneven development, for the strength of the user is exerted only in one direction against the action of the spring and this operation does not engage all of the muscles associated with the arms. An improved form of this type of exerciser is that disclosed in the Spector U.S. Pat. No. 3,834,696 in which the telescoping bars are hydraulically interconnected.